그누보드에서 배너관리 이미지를 반응형으로 넣으려고 하는데요 채택완료

<tr>
        <th scope="row">pc이미지</th>
        <td>
            <input type="file" name="bn_bimg">
            <?php
            $bimg_str = "";
            $bimg = G5_DATA_PATH."/banner/{$bn['bn_id']}";
            if (file_exists($bimg) && $bn['bn_id']) {
                $size = @getimagesize($bimg);
                if($size[0] && $size[0] > 750)
                    $width = 750;
                else
                    $width = $size[0];

                echo '<input type="checkbox" name="bn_bimg_del" value="1" id="bn_bimg_del"> <label for="bn_bimg_del">삭제</label>';
                $bimg_str = '<img src="'.G5_DATA_URL.'/banner/'.$bn['bn_id'].'" width="'.$width.'">';
            }
            if ($bimg_str) {
                echo '<div class="banner_or_img">';
                echo $bimg_str;
                echo '</div>';
            }
            ?>
        </td>
    </tr>
    <tr>
        <th scope="row">mobile이미지</th>
        <td>
            <input type="file" name="bn_bimg_m">
            <?php
            $bimg_m_str = "";
            $bimg_m = G5_DATA_PATH."/banner/{$bn['bn_id']}_m";
            if (file_exists($bimg_m)) {
                $size = @getimagesize($bimg_m);
                if($size[0] && $size[0] > 750)
                    $width = 750;
                else
                    $width = $size[0];

                echo '<input type="checkbox" name="bn_bimg_del_m" value="1" id="bn_bimg_del_m"> <label for="bn_bimg_del_m">삭제</label>';
                $bimg_m_str = '<img src="'.G5_DATA_URL.'/banner/'.$bn['bn_id'].'" width="'.$width.'">';
            }
            if ($bimg_m_str) {
                echo '<div class="banner_or_img">';
                echo $bimg_m_str;
                echo '</div>';
            }
            ?>
        </td>
    </tr>

<?php
$sub_menu = '500100';
include_once('./_common.php');

check_demo();

if ($W == 'd')
    auth_check($auth[$sub_menu], "d");
else
    auth_check($auth[$sub_menu], "w");

check_admin_token();

@mkdir(G5_DATA_PATH."/banner", G5_DIR_PERMISSION);
@chmod(G5_DATA_PATH."/banner", G5_DIR_PERMISSION);

$bn_bimg      = $_FILES['bn_bimg']['tmp_name'];
$bn_bimg_name = $_FILES['bn_bimg']['name'];
$bn_bimg_m      = $_FILES['bn_bimg_m']['tmp_name'];
$bn_bimg_name_m = $_FILES['bn_bimg_m']['name'];

$bn_id = (int) $bn_id;

if ($bn_bimg_del)  @unlink(G5_DATA_PATH."/banner/$bn_id");


//파일이 이미지인지 체크합니다.
if( $bn_bimg || $bn_bimg_name ){

    if( !preg_match('/\.(gif|jpe?g|bmp|png)$/i', $bn_bimg_name) ){
        alert("이미지 파일만 업로드 할수 있습니다.");
    }

    $timg = @getimagesize($bn_bimg);
    if ($timg['2'] < 1 || $timg['2'] > 16){
        alert("이미지 파일만 업로드 할수 있습니다.");
    }
}


$bn_url = clean_xss_tags($bn_url);
$bn_alt = function_exists('clean_xss_attributes') ? clean_xss_attributes(strip_tags($bn_alt)) : strip_tags($bn_alt);

if ($w=="")
{
    if (!$bn_bimg_name) alert('배너 이미지를 업로드 하세요.');

    sql_query(" alter table {$g5['banner_table']} auto_increment=1 ");

    $sql = " insert into {$g5['banner_table']}
                set bn_alt        = '$bn_alt',
                    bn_title1        = '$bn_title1',
                    bn_title2        = '$bn_title2',
                    bn_text        = '$bn_text',
                    bn_url        = '$bn_url',
                    bn_device     = '$bn_device',
                    bn_position   = '$bn_position',
                    bn_border     = '$bn_border',
                    bn_new_win    = '$bn_new_win',
                    bn_begin_time = '$bn_begin_time',
                    bn_end_time   = '$bn_end_time',
                    bn_time       = '$now',
                    bn_hit        = '0',
                    bn_order      = '$bn_order' ";
    sql_query($sql);

    $bn_id = sql_insert_id();
}
else if ($w=="u")
{
    $sql = " update {$g5['banner_table']}
                set bn_alt        = '$bn_alt',
                    bn_title1        = '$bn_title1',
                    bn_title2        = '$bn_title2',
                    bn_text        = '$bn_text',
                    bn_url        = '$bn_url',
                    bn_device     = '$bn_device',
                    bn_position   = '$bn_position',
                    bn_border     = '$bn_border',
                    bn_new_win    = '$bn_new_win',
                    bn_begin_time = '$bn_begin_time',
                    bn_end_time   = '$bn_end_time',
                    bn_order      = '$bn_order'
              where bn_id = '$bn_id' ";
    sql_query($sql);
}
else if ($w=="d")
{
    @unlink(G5_DATA_PATH."/banner/$bn_id");

    $sql = " delete from {$g5['banner_table']} where bn_id = $bn_id ";
    $result = sql_query($sql);
}


if ($w == "" || $w == "u")
{
    if ($_FILES['bn_bimg']['name']) upload_file($_FILES['bn_bimg']['tmp_name'], $bn_id, G5_DATA_PATH."/banner");

    goto_url("./bannerform.php?w=u&amp;bn_id=$bn_id");
} else {
    goto_url("./bannerlist.php");
}
?>